1. Field of the Invention
This invention relates to semiconductor fuses, and particularly to electrically programmable semiconductor fuses.
2. Description of Background
Before our invention, electrically programmable fuses (eFuses) used in re-routing circuits typically include poly-silicon strips with a thin layer of silicide covering the top of the stripes. Passing current through the eFuse results in the electromigration of silicide material in the fuse. Electromigration refers the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is more pronounced in applications where high direct current densities are used, such as in microelectronics and related structures. With respect to eFuse devices, electromigration results in a higher resistance in the eFuse, effectively making the eFuse act as an open circuit. Thus, a large current density is required to induce electromigration in these types of eFuses. The use of a large current may result in a rupture of the fuse link in the eFuse.